SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfc3a45df7c9b1735ef0e9bb34dd9625cd05a063fc20dc53f37d2d62665f9f37' 
  AND token = 'SChgmsWJWpZOvdH/D5r/8Vz7x27JKCafRhngSYb+bd8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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