SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3aae01a8d68cd1ba521a2f09265dd254a8fd2a3b229f3bc0d033d43461e631cd' 
  AND token = 'AzgbRiIygJ86hmtUmKnWfSep4Icbs4H5rcBN8/RSNLE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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