SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbda6951349579f232941ace60cb089939443eac782a803f0f5f5f0209ab7899' 
  AND token = '/s9VNBkcQmmaEclf5zcbbJTvkX6LwejwS1RFpVU3uRQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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