SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4da62a147921a3a016b00e0b8e827b21eadb01f75befefffa69652e371f80d13' 
  AND token = 'FJ+LW0HvmMFU5BEdr6C52m96JSngu6sBx0ldsGlCJWM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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