SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82419a6bcfb082adf24bdb4eb862fd9babe24c5d1135ed9fcd9370a3d11fb421' 
  AND token = 'LcnW5v2IxZbB/k68HozqYkmQkCYkf3n/6BH+omS46d4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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