SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cab706ee13bd95b26bdeff002faa43acfe5893b3ac57d32801ef876742a93d21' 
  AND token = 'RvlwrdHlDq0IPjy4Yiudoae46o+DIh4bjVOY8YlbYgM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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