SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd52fca9624506562b03f28e07c22dfc386114dc5a7313b1251b9346d4c85562' 
  AND token = 'Q+TU4UGbL5a6tRIHfZ5hGh1WKxCy4rBYngmp+mbZIMw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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