SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca196c68e89f5d6c21a89e39a7a07630c2a5a259999ea03e7d923a7a98472f7a' 
  AND token = 'szPGi84l+0jquq+QQfU4+CAZvTizl/bMcxiPKKJ0Phg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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