SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5bc7c4a2b463eb16efcaa59b1b749b98f077230504315736e425ef16fffd7c0' 
  AND token = 'LJYrs5B802k9l/DYCPBQox+YUMiMEVyNr4q0ZlfTw3o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}