Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '784c3e99e81cf2c36b7fa320e0f4a37080a7f857c7d4d844b2eba13ddcb50820' 
  AND token = 'Rkw1EWYJPe6YixZ2yZbdcmRNvnx+UVeoTRByOUWBSfI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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