SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89d7c282295fd654bc9e7a1fe8382ccd834585acc0965647559feb19c1421983' 
  AND token = 'jFjbFiwHvxekou4k3JU89XZCPd5dfIeVJpXXBoHBcCc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}