SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e71ed514b44abd15555d9ac82e5ffb4060c90bc8d44fab20ebda7930c1c1f42' 
  AND token = 'pUEBqgG2Xhdg81gSFqN1JGpTPyUfURKMClP70gHZ4uQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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