SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '276ab5aa47a1657476f9049f0798f6ae46cd7b9c0eac479877296c23d9baad64' 
  AND token = 'YvZfqDioP0hTjL/BxujlSgp5PL65ZIxl/egBmiN8wEM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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