SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '892383a645e38db8e1509d728f79a0de0dba03ffb56858768f4337806de2bbe3' 
  AND token = 'tTXa8E82iwdgova1FAQpdQgZqTGX9jl90cf5ZVGIoOo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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