SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e37ccb2fde77f8e32a908f5dc7500eff90e66f51a57979a837ce74394bfcc60' 
  AND token = 'qArJGmEsoHpDStsIFUIHgS2g627KzV13iPbQ5owQY18=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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