SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '628d82ddc7bc4b22b750328f8274e7920fafdcfd23dd8318f25588f9ea755638' 
  AND token = 'l3RTJDbDCe2AeKrz80ORhAQCLgtZE+EUiPY/RWRiCGs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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