SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44e17bd026dbd4aa67abb1ba8132bf2aa722e65616e027dab40fd743ee98a6e1' 
  AND token = 'mjTdEbTB1NjY3L7uQcquhnyyOjwy5RbLY0LF+3I+LzM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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