SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52f23113cda0e773b200a95c65d46944422b552540044ecd29f818d27ad917e6' 
  AND token = 'wCkrNzBjjshgcgljiWGGio/BX6ImsUZ6MTS4Npvz4co=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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