SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7dc0cbe7ba54efcf2f391898a59cbed03570508f9902094dac6ee60aa953bcd6' 
  AND token = 'CGDRrA0obBzsP0OwLbxEhYeVInHnxYTM2RpD/pmqJho=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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