SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ebc6a7f76d98402515604314453462b2984781d82e44f2a2a56c2477b08579a4' 
  AND token = 'MWQi0PFmTU9G8oBS/+RaIJI8hgmu31J4hVdA5zZFXfM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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