SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd25a18da431d877e3e862989ff7ccd4a48adddab2bcf791ef7ffcede20edebc7' 
  AND token = 'cFU0ZWsPQa1LAZV5dagubIjQecQJvGbQvnEWVW8ssbU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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