SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dde7b045d297306a59ee1b5f1e4e0a4b11e7516a7cc340e8f46245404e3909f7' 
  AND token = 'NWKD1QenSKKJdMV2QPU8mOjaOLtM9m1YynI1L42qw1U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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