SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b89fcef4befc79bbf77c80d8159b49d3be1b8592880c51fdd28a7b7b53f25f2' 
  AND token = 'TJ6zFGYFYROHXXxC+9di8W9N0W3gcXYwq+fCPiN0UUQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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