SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23ed5f80c44e74df866f0c696d854bfb5b907b7394c48db6c882690302dac13c' 
  AND token = 'vDbiwotnPOrpvGrza7p6WqWhneAbEbGOohqRjqemrpA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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