SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47b5c590a15dfdfe0138abc0e02a899eef2f1efd195f133fe85e9a3b142d4b93' 
  AND token = 'QXsfkJYLz5RIiYN/O4M2n7FyluLGgNZlHMijqbmf/yk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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