SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'beabeb1170e4d580c56fe75c06475a31830e0c158b9efcffb5b89cfd101a8dcf' 
  AND token = 'FmjRZKfkBN+Apkn/QrvqnCHoDog9VxNLCprhZYdLh+s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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