SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e7c3a15ff7c2ced71ce3e0a1dd4e9e7a91c21920b11d9340df0a812748c3229' 
  AND token = 'IzkN2FCA++bMWf0uHDpAFMCQTum460vg7Fmdzvv4FL0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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