SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9eb0c095e2c410f8f6cfbadfc92455e5b43a32b791f442065d41c82b6254f36' 
  AND token = '8wc2bVUwPhs1xNvIdTX3EPVcuEk0X7gBc+oTsdQ+Zak=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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