SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '958429935f10d005d76e0b4b8b2ca13528eb4d2dfa8533a7c43a1f5c59df524c' 
  AND token = 'r597HAGBHcyDNqj4/OPNdaEN1SJpVmHWsSBX4UuoQdk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}