SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32742512812992e406b75caee23cd3950a1aefd888379d74abbda0e89ace46cf' 
  AND token = 'um/R5m577rYmmui4Wet4Hq0wQYhze2QzjDQQfg0Xw28=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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