SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe48e4acf0662e70e959b3d2624db772eb83bef0997875f64c235c14eb5b6b0d' 
  AND token = 'y/plYAq5+Q3KMgQ0qJTGFWJ3c2Fbh8yPoOYRSzwcujg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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