SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d34a2b845b6d83929f4f4555a28ec298d223fac7606938e9a3b921629b660a0' 
  AND token = 'sH5OeN+m+hGjArgM32gAcmDRfpiJtZqDo+L0aRy+srM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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