SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b8b5b4162dd1df7c4004c4667671f45ca5226e5d087756e2a8112a133f8ce93e' 
  AND token = 's+AqwSf6L8sGrKfJz4lmjYhHJBWy0IEoV/eUHxpoFh8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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