SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0b402fa09f693d42e0616a67bb85259e843327bb555231529e5a0c82d3f098f' 
  AND token = 'kt8PWYh5n+dPKTNj9EJzzpe1V9FGeyJUhhiCTnLp42Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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