SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca9241f048dbcf4331c3735d185910c5b4fc9b03f60fa3e5879baf63fbc49635' 
  AND token = 'vNyMiAYMCq9K6FY7cXAdPFo+JgJiZ/EzfXAH26vjr54=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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