SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0a63e1a10ef6ccda966fd5821339146346890290fd2007800b9f9f25e8cbf27' 
  AND token = 'kkX6z1KmpSIgR3AuzdRh/az3gvfKPjXAGBdobjlzQA0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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