SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '142eaee5ec2180b2b6c0f50a75f1eea883b22310c99915079693e48df6f7e8d1' 
  AND token = 'czZIW+MdHLbTmgl9GQ/pkhzYgm8zUP6nUWLDLSujtwA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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