SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84f7f8d16eebee6bebd58d5011370adce4c80081b7ac6c41a34f24f0ea51b035' 
  AND token = 'eawm3ynUmozC9mphWmfcpjPB03O0AcN8g0E3N4tX5Fg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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