SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de4d23e7faa6ad3cc2451aebf0fba71e7ec25147e77be55dbe39252312f15814' 
  AND token = 'dlrF13Qu7aTtfkZjIQlaqhLf+IaXB7dPqgn2IdYM8S0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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