SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0487809d60564c87670597e6928d5609832423584e0b9201bbb0c0de9061185c' 
  AND token = 'JdscmhEhtg9LW2A4HwJ+q2IKI8q3hdcKAmUZ9bkwOms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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