SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27bd75d1ca7077b95d1d5efd265bd693a7e4774248e3a181ceb93a2de9394074' 
  AND token = 'zSNTZhRKOIZPq3B6QkVX25Ah+StBzEfuteYh8/DkcP4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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