SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4c9efe09d831a61f53a5e562cc868e86b02223765173e3dae468f6f2394e95c' 
  AND token = 'Zf3R9ZxiW/nr63eRxCPlEvcYGw0SyQg9CJG1Sz8qpB0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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