SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '613646a6c1be2f74294acaed9f2cdb8a5361e61628d1f770283552b2c40cae22' 
  AND token = 'CQLkuRcFcwCo3Wwpj9+P9wFnLyu4bFm2dFXv1rmP6hs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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