SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03a25b7d1e5b3a6cebd2c7f76721043b5ae97e5caf50092c6aeb485b6e239ad0' 
  AND token = '8lCeaHroODydPmAbbq6fgfM3HweDcnq/c4o9JoEpY7c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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