SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65e36a74c6548ac752822ff2e5c335d3ce6ba91aa9a6fe7d0dec2039599baad3' 
  AND token = 'hDzU9kgLMxAg6pnFEblerkdOuiz6aFNrA9NLt78pkt4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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