SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14250d307a9b5f32a010f13104c1eed3982483200cd78da5c49d95dd7875a830' 
  AND token = 'JVyFdH5Nh2P1cSuqv3r5b0WcXcJ7F5WBO8F6LDEzMws=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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