SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17affe90373e2d47d78b96327e641c3d0acf65fdefe6701799c42dcfc3c89086' 
  AND token = 'QYC2BmxsmJ/C8vfoxwuILnGHhdWsNpSuXRc8AZO+2A4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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