SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ddf554a64b840af69f6dd0706d4a65ff595ac1b83a6cdaead51027dea650f475' 
  AND token = 'soxXS7IPn3y4PxFtveQZwp94FX2sjZqxKP4dUugYE8E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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