SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14c53494e28d7c64d275aa0beac383d39307943fcea9e434bd13139174f03a45' 
  AND token = 'TCdMBckNvlETAV62dD+0a4XrnbERQ26s2zIlxJqhYGs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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