SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5eba18350535ad821a1db134608cbb5bfc5182659dbf791643202164f78bff15' 
  AND token = '2cqtYyqx2KqERvYxZsE309KYu/mKGUNtoTT+hVmgdR8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}