SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb2c92f48c7bebef8d3fef76175bdf973504bf9658cdcbcc8f9bf8b6182fb774' 
  AND token = 'w/YSXrmc82MCs8ptPfdNfw8w89cxxarEvuJ93AZ3o+E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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