SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f79988358512764ab4973cec26d8190e652e666301c0604b0a0e46216e29e95' 
  AND token = 'CQTT1t2zd53PN2k+USx7lq6jh4ZcpplO7fAFZIS0/Bs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00011

JSON explain

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