SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4cfed71f79e243bec33fa1245093fc25dd0f68277f5f6599f5457b0db5338f77' 
  AND token = 'IPnonij8IEq+MVwOZURGVGE7Auq0wzoW9B1bNE/8Wto=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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