SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '094104fa8b258234744d55074b7a262378f346f63c0a1919bb2eb268f0437a78' 
  AND token = 'pOjyOxUEEQgy0pAaL/j8cbmQASvl8UpVS9+PxKkt8XQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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