SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00dd50f9522038ba95273390e857f23423f880700c42cd7cbad65c5db73f50c3' 
  AND token = 'zH+7bo8hbIlXClJF9Y4CmWxiUrBamjw87Ma6xPwsK4M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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