SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0cc0ca59ef0814e67747598a215bb3eaab5b7f9a5afb41cef37051e4c35bda1' 
  AND token = 'LjXBkmU9OSY3JM9GqIBzrkL0vzN5o903rfixARNCsTQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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