SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afa11cf4113dc1489933f9545b6db354bbbabbcf8b19c9fde637342d7cfb77b6' 
  AND token = '5WfGdqeAlLZbR/Ic2ohMIc4OjWRavkMetSaGoPmNuIo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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