SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd2d869923dc91bf42faa4d80a3b190f5fa707c00ae693140672718ec6c20d79' 
  AND token = 'T/Tm6qZS/l61psxtNJcfooryaW0Z+sXd/99geNZp90I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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