SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e7f467433ba99616cf8238849452026cd69a6f76d5c66f995796c86604b34cc' 
  AND token = 'ixeC96rGPSKIxI/MuL9/plmkUqLk86MYPVBe8vK2YY8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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