SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bba4b70f0c0dba15fedaedea8a11df475c9013a44bb7dda95cfd844775e1e64c' 
  AND token = '5FXcajZ6o9Yo+dVZ/F9h/QRMIyzQnba4gaAGDWGG0AE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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