SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfae17f22ce0c7222e4731c2a58a9953d57963dc13366947eb211ccdb719a59f' 
  AND token = 'UpmkQQi/VUWhfE6Ni5adDJGqK4EGmQnNTa6k7QyzXE8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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