SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '464c10cf55b17b08400d9854fbb49b1abc71978c259894b55d106f67ee817de8' 
  AND token = 'BLKXkHo2Kg6Swbu1sK0EKIYxPjg5whc9tbWhbVehQA0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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