SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '91f26370ee3b4784b32ae26d2796b916f50a068f104a73b0c88bdd235e75c634' 
  AND token = 'zbTWuT2GZgfLpGCSWkWx7jEmb3ikmGq0jBmceYGY/bc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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