SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e573c50512ea7509aa091d9907fb3689a8289922c1e10380dc3d0f35a3460ed' 
  AND token = 'gkpe0i6TEmeorz6aJ2WFf2l1K66G3EnLdgi1b7hOsyc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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