SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9fdadf9655acd69ab9a435cf46076543567198b01201b2b1a8e2363d2bd5f93' 
  AND token = 'qsWpwOs3VgRKHCSL5OUGRQ0ZNCmgEfuwMH+C3cQ/IU8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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