SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75033aab8f62d6ed34c40b15cdda2208b35949c1c8fb9728ef82eea4f22d7696' 
  AND token = 'HmYWopwNGsNmAJq2LZX9ChMWCFmghYEQhCavNQOnHF8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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