SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd124a1867428273fbd60bf417fb1c69ee90d63fca63b2ebc8c17dea13a7e8c81' 
  AND token = 'atBWM6wo2QX2g13ICNKkhin+StwkTIE7snmOrF4cCJ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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