SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6186f885d56095ebae188909a860fc2e575db5c64929fa7aba356ea7fed41b82' 
  AND token = '6wp+0yfyuvBFrl/Q7EkRottViznY4IFIjW+4h0H+FNs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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