SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a13b4073b55c0b7a461bdd107470eee7cd257d2cdf15218bf7dd492f9d4543cd' 
  AND token = 'hmfooPEyhKp+zsWsWw1LMQ/f0/RqDYvvMbyjkumhips=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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