SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5dbdcb5a4b51ec9c3ec6989204ea54604f775a82f2f13350e86c830abe0c3ceb' 
  AND token = '+Iciwld4Wl3KPTHFdGjKUBRhWFXV+wb1QCNJKHIzG20=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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