SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0358b4eef9f17bf15d9b595bbef2fb8561fcbed14adfcb9c02d6027db3ee9a40' 
  AND token = '4XWYqDYAKu86At5Q/cN0Q6GAg0wYpLrMWN4zs3mbzo0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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