SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b1cde835d7cb6761003f559afcbc6ec384e641d56d439c1720b24ae8b322cc5d' 
  AND token = 'G94B7OaQRFYE8UpG/MbnTxwUdMP6lcT1ZMw1QCDGWVI=' 
  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"
    }
  }
}