SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1abc2a4c10162cf9d04a92cb4d81571500bb59b063a0694285489161fe78958' 
  AND token = 'AET/CGOuLwUvHwUznxFAV1z+qCNwsq7FH8imOI8Rw38=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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