SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9ae272f697119b519221955f10d9f57e970b7547aa627acb7e816c462b7d847' 
  AND token = 'G2Jc36EH77A5TSnXIjwj28ZjBVXP9Em5c/UPxayB4y0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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