SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6be9a7c99d4bca3747f43fd283a2661c892660018133dbcd761318cd2cf8848e' 
  AND token = 'QE7IZ21fLyIffkmN55wsYLUkCRXQXkX3h4AApTvUIu0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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