SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a43a1fc583653bcc5bb78945ebe0b7e3cf8fcaca274d37a5b62f3538e0e3143' 
  AND token = 'FYdcSrmi47Kqji1JCBfeMAYr544kBn2al+pvjBGlIZM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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