SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72ca3b4b22dfa83c057d09cf05a139bec6bbce65d52fd50e150dcd36689afe62' 
  AND token = 'JS1slTlnxwG7E6mrfmWr6R38grt8aq+ix/SZ7q6TuWM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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