SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c738c72392fdab48a58d60b714bbe56fbb9e5421c62138eb949f198d1856125b' 
  AND token = 'B3ik4pKG/eiduzpoKggSG37EQPD8ZXmvZ9sqlWiLNoQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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