SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '90e6e3874317acc08e365bae41a0d993a16562a4dfdb61fe890b5f8eb668157c' 
  AND token = 'lb5AeRnOIloQPFJWP/jHvei9khjVJbBwFahCXpnsgwc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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