SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '91b5024d04895eb2cf81ef0ff42ee9c4ce4f982764aba86b26cde56971f0aadb' 
  AND token = '4qAJWorA4Rr4K2douCR6HIklxg6SkufTSa7IA8eF3kA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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