SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82461de2e249a8686f2c761de4d7dca734e4d5b7800b16eb3616e51d9f32cea5' 
  AND token = '0UfCZnOw7Pi9HmM0IaVhp3rl/TopC8x1VUjxIyGDgkc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}