SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5647964df533afc38e40abefb555755ac41a69b0cb9820941cc1f2eb0062335a' 
  AND token = 'AQKGxkS4cJVoWZZPjw/DQF38t/vpz1iQQvuBPxXF6bg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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