SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2dcc458e281c25058a8718d343b16c158f8f1461ae09e318647d330b6026e82' 
  AND token = 'D/fgfrrLKLfmKa8cLtZlS50yJasMtHF7IvwKwGLNx4A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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