SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1fb3d69e15834b58ba2a9dc3c10ba643f8d2df2dc3e89bd5082c6b7df53814e' 
  AND token = 'JVBwDTWCuS4IyJVxnFpmzsP9sa5/BE2GHyQdgYmGmnI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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