SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99e0501659747c06170541cb3ffa0f7bbcf3a4ffc52e30ad1662be405c4f9bfa' 
  AND token = 'Ae4Q2KVbsvSqoz7Db1WoFLsfvtl093+c+HlfnHSzPwU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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