SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48a276601acd49594c86c322db7a1bb761ad20ac9b442117c2807def8eaa7032' 
  AND token = 'FZzYJwzQt69AHgDFplsMrIMEdZXyC6fYB3W6qnGwstA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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