SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a5cc2a3bd9543e663dd5d3132a798ec1d3243186f076b63e5b560113d41ae90' 
  AND token = 'gDdE+czWSHubqRqHJV7zPP9mBYpkVKa2ijTT3rY90m0=' 
  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"
    }
  }
}