SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbec2768138f7dc04d603d2e65d3958a2fe67ab895e3ea09dd8ba0ecd65530c8' 
  AND token = '7qxGi0qqYx7M8UA0uk9pcHRuQmC9aQr4JJ+SbCpLPLw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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