SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '90f1cbb60aa47134b3bc58c754584924e5915fdc04859b66b2d877744aa7f9b3' 
  AND token = 'nc/iGAranIRlRoMwQZ1oXB7S+Z2qvPSvVANjV5sXHmA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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