SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f724e60ae512fa54ef2966925e62b0e32db1904cbd96e2acf2a99263d961da9c' 
  AND token = 'mA7Ntp98PHPN2KMaIy3+spOpknL+Y9s+hFKUYG4uk3U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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