SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2f8485b39a19aa743ea817c763603b6b2057847bb830d31cce7cf2b296cb0ab' 
  AND token = 'rlnejakzgtj8cDiU1wvsDOy5Rahcgy205yo3OKe3bzU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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