SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6cec782cbaf2932bc1c5caded9999b2252622c6baf9670ab09278c691abc4752' 
  AND token = '9b4ahbsO5Uy1JVep/VbH8OoMEuZgPAwes7F3bWQb5lY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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