SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94cdaee891cf70b196ed921b4660fbc57f3d6c14a9d6c303803ac396929820cd' 
  AND token = 'j8/j7bN3ry5ZySZiGKExM+9FYCMhyT6oMC89sg2DKgo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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