SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44bae9c5c6ea5c312d7b91a6dc684852c7898edb00e357940103ab5c15e8ec21' 
  AND token = '9HCt0dPPtUlYHCpESOopenfODmHgrjB9f2Xf6yNxsi4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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