SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e1f067155a088f3fbbd95ae4e9f3e7dd5ab357a8322257993ff9850de66d66d' 
  AND token = 'aoCsWXrqs8Jxj3XfvMCfhgJfRjS5CcrKDZ4mQBDKP3w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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