SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f439fbdd1436ef97531318af3fbbd97b930cefb23db9f1d96942cbe25acff60' 
  AND token = 'u2P5twmfJmiZW4KfSWY5/+A74kExIuKF1YQ8oGSduT8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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