SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6722f80869e239d4c2a4926e8b7237e953f1d457d2c03123fda06963a76a72d' 
  AND token = 'YjQzxPqk54/w6qUuZi/B0N2uVcG60Hzd/K2LANsTVBc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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