SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a7b81489942db91b7d1aa6d2a0a00af279863a90428662278e4107ebf230371' 
  AND token = 'lRmRADT//8rWabMzfCaRF1WdSgRqC91KD3CniTs+XZs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00064

JSON explain

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