SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ef541d9138c62a663324e1d272fe0eb00d97b66ab81464519798549143a9756' 
  AND token = 'xnGvv9jAD1PZh9DNpZJtdGoQjsfVaCO7Mf0CQYGC/Cs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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