SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5034b95d74e97c1b8e38ebd48ac2c4773f51bde7c957a9146a780a97371f416c' 
  AND token = 'sfONY7lkgnaacj46zfnMzDVGJwI9vlDoN8xsc2Uryvo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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