SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db591fe5655703f865e6f0a122c9c3954e60649b21496def9e4d1ea88247af77' 
  AND token = 'XlUL59/hQqu+0tRZUhFHzi2EhyxdWfizOxxc5LcyylY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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